A Parametrical Study with Laser Sheet Visualization for an Unsteady Flapping Motion

2006 ◽  
Author(s):  
Dilek Funda Kurtulus ◽  
Laurent David ◽  
Alain Farcy ◽  
Nafiz Alemdaroglu
Keyword(s):  
Laser Sheet ◽  
Flapping Motion

Laser Sheet Visualization for Flapping Motion in Hover

2006 ◽  
Author(s):  
Dilek Funda Kurtulus ◽  
Laurent David ◽  
Alain Farcy ◽  
Nafiz Alemdaroglu
Keyword(s):  
Laser Sheet ◽  
Flapping Motion

A model of flapping motion in a plane jet

2002 ◽  
Vol 21 (2) ◽  
pp. 171-183 ◽  
Author(s):  
Oliver V Atassi ◽  
Richard M Lueptow
Keyword(s):  
Flapping Motion ◽  
Plane Jet

Characteristics of Preheated Bio-Oil Sprays Produced by an Air-Blast Injector

2010 ◽  
Author(s):  
Heena V. Panchasara ◽  
Ajay K. Agrawal
Keyword(s):  
Laser Sheet ◽  
Inlet Temperature ◽  
Mass Ratio ◽  
Ambient Conditions ◽  
Air Blast ◽  
Visualization System ◽  
Radial Profiles ◽  
Significant Difference ◽  
Bio Oil ◽  
Temperature And Pressure

In this study the vegetable oil (VO) is preheated to reduce the kinematic viscosity, and thus, improve atomization. A commercial air-blast atomizer is used to produce the VO spray at ambient conditions of temperature and pressure. Characteristics of the resulting spray are measured using a laser sheet visualization system and a Phase Doppler Particle Analyzer system. Experiments are conducted for VO temperatures varying from 40 C to 100 C and air to liquid mass ratio (ALR) of 2.0 and 4.0. Results show a decrease in Sauter Mean Diameter with an increase in VO temperature, regardless of the ALR. Radial profiles show larger droplets migrating towards the edge of the spray and smaller droplets in the interior spray region. Results show a significant difference in distributions of mean and root mean square axial velocity profiles as the VO inlet temperature is increased for a fixed ALR. Higher VO inlet temperature and higher ALR produced a narrower spray with smaller diameter droplets and higher peak axial velocities. Overall, this study has shown that preheating VO improves atomization by producing spray with smaller diameter droplets.

Laser sheet dropsizing of evaporating sprays using simultaneous LIEF/MIE techniques

2013 ◽  
Vol 34 (1) ◽  
pp. 1677-1685 ◽  
Author(s):  
Wei Zeng ◽  
Min Xu ◽  
Yuyin Zhang ◽  
Zhenkan Wang
Keyword(s):  
Laser Sheet

scholarly journals Reading the copepod personal ads: increasing encounter probability with hydromechanical signals

1998 ◽  
Vol 353 (1369) ◽  
pp. 691-700 ◽  
Author(s):  
Luca A. van Duren ◽  
Eize J. Stamhuis ◽  
John J. Videler
Keyword(s):  
Flow Field ◽  
Laser Sheet ◽  
Surrounding Water ◽  
Encounter Probability ◽  
Velocity Gradients ◽  
Swimming Motion ◽  
Image Velocimetry ◽  
Temora Longicornis ◽  
Leg Movement ◽  
Swimming Leg

Females of the calanoid copepod Temora longicornis react to chemical exudates of male conspecifics with little hops, quite distinct from their normal smooth uniform swimming motion. These hops possibly serve to create a hydrodynamical signal in the surrounding water, to increase encounter probability with potential mates. Laser sheet particle image velocimetry was used to investigate the flow fields associated with these hops and to compare them to the flow of the feeding current of an adult female. During, and immediately after a hop, the flow field around the copepod showed a marked difference from that of a foraging animal. During foraging, the highest velocity gradients were located around the feeding appendages of the copepod. During a hop, high velocity gradients are located behind the animal. About 0.5 seconds after the start of swimming leg movement, effects of the hop had virtually dissipated and the flow field resembled that around a foraging animal. The estimated volume of influence (i.e. the volume around the copepod where the animal has a significant influence on the water) increased about 12–fold during the hop compared with the situation around a foraging animal. Furthermore, the rate of viscous energy dissipation within the copepods' volume of influence increased nearly 80–fold. Hops may serve to increase encounter probability, but due to the short duration of the effect and the high energetic costs they would only be adaptive when other cues have indicated that suitable sexual partners are in the vicinity.

Out-of-Plane Motion Effects in Microscopic Particle Image Velocimetry

2003 ◽  
Vol 125 (5) ◽  
pp. 895-901 ◽  
Author(s):  
Michael G. Olsen ◽  
Chris J. Bourdon
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Laser Sheet ◽  
Plane Motion ◽  
Entire Volume ◽  
Measurement Volume ◽  
Microscopic Particle ◽  
Image Velocimetry ◽  
Out Of Plane ◽  
Signal Peak

In microscopic particle image velocimetry (microPIV) experiments, the entire volume of a flowfield is illuminated, resulting in all of the particles in the field of view contributing to the image. Unlike in light-sheet PIV, where the depth of the measurement volume is simply the thickness of the laser sheet, in microPIV, the measurement volume depth is a function of the image forming optics of the microscope. In a flowfield with out-of-plane motion, the measurement volume (called the depth of correlation) is also a function of the magnitude of the out-of-plane motion within the measurement volume. Equations are presented describing the depth of correlation and its dependence on out-of-plane motion. The consequences of this dependence and suggestions for limiting its significance are also presented. Another result of the out-of-plane motion is that the height of the PIV signal peak in the correlation plane will decrease. Because the height of the noise peaks will not be affected by the out-of-plane motion, this could lead to erroneous velocity measurements. An equation is introduced that describes the effect of the out-of-plane motion on the signal peak height, and its implications are discussed. Finally, the derived analytical equations are compared to results calculated using synthetic PIV images, and the agreement between the two is seen to be excellent.

Slicing photofragment spatial distribution by laser sheet ionization

1994 ◽  
Vol 224 (1-2) ◽  
pp. 1-6 ◽  
Author(s):  
Kenichi Tonokura ◽  
Toshinori Suzuki
Keyword(s):  
Spatial Distribution ◽  
Laser Sheet
Sign in / Sign up

Export Citation Format

Share Document